The present invention relates to a laser computer output microfilm [COM] camera for the utilization of direct read after write [DRAW] film.
More particularly, it relates to a camera of the above mentioned type provided with a film gate in which film is moved in one direction for example with reciprocation by means of a film transporting device in an image stepped manner and also is moved with reciprocation normally to the movement direction of the film parallel to a film plane also in the image stepped manner, the camera has a film supply device prior to the gate and a catching device for a microfiche ready to use and produced from the film. The computer-controlled laser beam in the region of the image field of a microfiche image is deflected by means of a rotatable polygonal mirror from the beginning of lines to the end of lines and back, and is deflected by means of a swinging mirror in direction of the next line and back. It is projected by means of an objective sharply onto the film gate or onto the film contained in the film gate.
Such a microfiche making camera is disclosed for example in U.S. Pat. No. 4,427,292. In this camera the light-sensitive sheet film is transported from a cassette into a picture taking gate and back into the cassette and finally developed. The sheet film is moved by means of a transported roller pair in steps under or over a projecting objective. A complete original side is reduced into a microimage, so that a row images in the transporting direction is produced. The image gaps arranged normally to the transported direction are obtained by stepped displacement of the complete arrangement normally to the transporting direction. This type of the known microfiche taking camera has the disadvantage that on a produced microfiche no completions or supplements can be performed.
A process is also known with the utilization of a thermally treatable, light-sensitive microfiche material, in accordance with which each individual image is first made light-sensitive by thermal treatment directly prior to the illumination, then illuminated and then developed by thermal post-treatment and fixed. In this process only the image field of a single microimage to be illuminated is sensibilized and subsequently illuminated and developed, and then when needed the next image field is treated in the same manner. Therefore, in accordance with this process it is possible to take a row of microimages of one step, for example document parts on a microfiche, and during further carrying out of the step, for example the documents to provide further associated microimages later on the same fiche. This process involves not only a substantially expensive treatment of each individually produced microimage on a microfiche. Also, the production of completions or supplements on a microimage which is for example not completely used is not possible, since after the sensibilization, illumination and development of a microimage it cannot be made again light-sensitive.
Finally, a laser COM system is known, as disclosed for example in the Journal of Applied Photographic Engineering, Volume 9, Feb. 1983, in which a metal layer arranged on a transparent substrate and coated with a transparent protective layer is used as a role film. The computer-controlled laser beam is directed per each image in point-like manner to lines and gaps on a so-called DRAW material [direct read after write material] and melts the points of 0.1-1 micron in diameter from the metal layer, so that the film becomes transparent on the laser beam-illuminated points. The roll film after the illumination is cut to microfiches if necessary. This system has the advantage that no film development is further needed and that arrangement of the material can be performed with full daylight. However, in this arrangement it is also not possible to bring additional microimages later on an individual illuminated microfiche which is provided not with a maximal number of microimages, for example for microfilming of documents supplied in a time sequence one after the other to be associated with one another. It is not possible with this arrangement to subsequently complete individual microimages. Moreover, in this arrangement there is a disadvantage that both the film gate and the film supply roller must move transversely to the film transporting direction.